Transposing key-board for pianos



(N6 Model.)

I. BOOS. TRANSPOSING KEY BOARD FOR PIANOS..

No. 427,826. Patented May 13, 1890.

m r /Jo/ Co f 6 W vsw v a T w N 2% W UNITED STATES PATENT OFFICE.

IMRE BOOS, OF MIIAVAUKEE, \YISOONSIN.

TRANSPOSING KEY-BOARD FOR PIANOS.

SPECIFICATION forming part of Letters Patent No. 427,826, dated May 13, 1890.

Application filed October 16, 1889. Serial No. 327,222. (No model.)

To all whom it may concern:

Be it known that I, IMRE Boos, of Milwaukee, in the county of Milwaukee, and in the State of Visconsin, have invented certain new and usefulImprovements in Pianos; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates to pianos and organs, and will be fully described hereinafter.

In the drawings, Figure l is a section taken through the key-board of a piano. Fig. 2 is a front View of the same, partly in section. Fig. 3 is a broken plan view of 1110 attachment that constitutes my present invention.

A is the key-board.

B are the White keys, and C are the black keys, of an ordinary piano.

D is a frame, preferably of metal, that is fixed in the piano between the two end pieces a in any suitable manner. The front rail 0 of this frame rests on the front ledge c of the key-board,while the side rails are curved so as to elevate the rear rail (l to a plane higher than that of the top of the keys.

E is a smaller frame than D, and the side bars of this smaller frame are formed with concave bearings g and h, that rest upon the front and rear rails of frame D, respectively, and are suitably cushioned to prevent vibration. The side bars f of frame E are connected in front by a bar E and in the rear by a rod G,which rod is passed through the rear ends of supplemental keys I J, I being the white and J the black keys. Each of these keys has a striking-pin L projecting from its under side, with its lower end, which is suitably cushioned, resting upon a key B or O. The barFis provided with upwawlly-projecting pins F, and the white keys I with recesses 7; to correspond, and these pins F serve as guides for the white keys, while the sides of the latter serve as guides for the black keys. Ordinarily I propose to provide the frame E with ten keys less than the piano on which it is to be used, and the front rail of frame D is graduated, as shown at j 7', so that the player may adjust frame E accurately to the position desired.

The object of my invent-ion is to enable a player to accommodate the instrument to the .voice of a singer without transposing the music by simply shifting the simplemental keys, so that the finger may follow the written notes,while the tones actually produced may be in a higher or lower key than those in the notes.

In making new pianos with shifting keys the parts may be put together more compactly than when these keys are applied to old pianos, but the principle is the same.

. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

An improved transposing attachment [or pianos, consisting of alightreetangularskeleton frame adapted to fit removably above the key-board and between the end frames thereof, and having its front member or bar graduated, in combination with a light rectangular frame supported mox ably upon the front and rear bars of the first-named frame and having its front bar provided with upwardly-extendingguide-pins, black and white keys pivoted upon the rear bar of the upper frame and having each a pendent pin to engage a key of the piano, the white or longer keys having recesses in their under sides to receive the guide-pins of the front bar of the upper frame, substantially as described.

In testimony that I claim the foregoing I have hereunto set my hand, at Milwaukee, in the county of Milwaukee and State of Wisconsin, in the presence of two witnesses.

IMRE BOOS. \Vitnesscs:

N. E. OLIPHANT, WM. KLUG. 

